1. Field of the Invention
The present invention relates to optical and electrical systems. More specifically, the present invention relates to systems and methods for sensing proximity to a target object.
2. Description of the Related Art
Missiles often require detonation of a warhead to occur a short distance before impacting the target for maximum warhead effectiveness. Particularly when a shaped charge warhead must penetrate an armored target, the ability to control standoff distance for warhead jet formation greatly impacts the probability of kill.
Fuzes for low cost weapons have traditionally detonated warheads upon target impact using crush switches. Other fuzes have also been deployed that sense altitude or target proximity for detonation. Proximity sensing fuzes typically operate by transmitting an RF (radio frequency) or optical signal toward the target and measuring the time until a reflected return signal is received to determine the distance to the target. The warhead is then detonated when the missile is at a predetermined distance away from the target.
Conventional proximity sensing fuzes typically require additional electronics for transmitting, receiving, and processing the RF or optical signal. These electronics usually serve no purpose other than proximity sensing and add a higher cost to the missile. In addition, conventional proximity sensing fuzes typically have lower precision at sensing the distance to a target located directly in front of the weapon.
Hence, a need exists in the art for an improved system or method for sensing proximity that is less expensive and more accurate than prior approaches.